perf probe: Add lazy line matching support

Add lazy line matching support for specifying new probes.
This also changes the syntax of perf probe a bit. Now
perf probe accepts one of below probe event definitions.

1) Define event based on function name
 [EVENT=]FUNC[@src][:RLN|+OFF|%return|;PTN] [ARG ...]

2) Define event based on source file with line number
 [EVENT=]SRC:ALN [ARG ...]

3) Define event based on source file with lazy pattern
 [EVENT=]SRC;PTN [ARG ...]

- New lazy matching pattern(PTN) follows ';' (semicolon). And it
  must be put the end of the definition.
- So, @src is no longer the part which must be put at the end
  of the definition.

Note that ';' (semicolon) can be interpreted as the end of
a command by the shell. This means that you need to quote it.
(anyway you will need to quote the lazy pattern itself too,
because it may contains other sensitive characters, like
'[',']' etc.).

Lazy matching
-------------
The lazy line matching is similar to glob matching except
ignoring spaces in both of pattern and target.

e.g.
'a=*' can matches 'a=b', 'a = b', 'a == b' and so on.

This provides some sort of flexibility and robustness to
probe point definitions against minor code changes.
(for example, actual 10th line of schedule() can be changed
 easily by modifying schedule(), but the same line matching
 'rq=cpu_rq*' may still exist.)

Changes in v3:
 - Cast Dwarf_Addr to uintmax_t for printf-formats.

Changes in v2:
 - Cast Dwarf_Addr to unsigned long long for printf-formats.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133611.6725.45078.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/Documentation/perf-probe.txt

@@ -61,11 +61,19 @@ PROBE SYNTAX
 ------------
 Probe points are defined by following syntax.
 
- "[EVENT=]FUNC[+OFFS|:RLN|%return][@SRC]|SRC:ALN [ARG ...]"
+    1) Define event based on function name
+     [EVENT=]FUNC[@SRC][:RLN|+OFFS|%return|;PTN] [ARG ...]
+
+    2) Define event based on source file with line number
+     [EVENT=]SRC:ALN [ARG ...]
+
+    3) Define event based on source file with lazy pattern
+     [EVENT=]SRC;PTN [ARG ...]
+
 
 'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. Currently, event group name is set as 'probe'.
-'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, 'RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. In addition, 'SRC' specifies a source file which has that function.
-It is also possible to specify a probe point by the source line number by using 'SRC:ALN' syntax, where 'SRC' is the source file path and 'ALN' is the line number.
+'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, ':RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. And ';PTN' means lazy matching pattern (see LAZY MATCHING). Note that ';PTN' must be the end of the probe point definition.  In addition, '@SRC' specifies a source file which has that function.
+It is also possible to specify a probe point by the source line number or lazy matching by using 'SRC:ALN' or 'SRC;PTN' syntax, where 'SRC' is the source file path, ':ALN' is the line number and ';PTN' is the lazy matching pattern.
 'ARG' specifies the arguments of this probe point. You can use the name of local variable, or kprobe-tracer argument format (e.g. $retval, %ax, etc).
 
 LINE SYNTAX
@@ -81,6 +89,16 @@ and 'ALN2' is end line number in the file. It is also possible to specify how
 many lines to show by using 'NUM'.
 So, "source.c:100-120" shows lines between 100th to l20th in source.c file. And "func:10+20" shows 20 lines from 10th line of func function.
 
+LAZY MATCHING
+-------------
+ The lazy line matching is similar to glob matching but ignoring spaces in both of pattern and target. So this accepts wildcards('*', '?') and character classes(e.g. [a-z], [!A-Z]).
+
+e.g.
+ 'a=*' can matches 'a=b', 'a = b', 'a == b' and so on.
+
+This provides some sort of flexibility and robustness to probe point definitions against minor code changes. For example, actual 10th line of schedule() can be moved easily by modifying schedule(), but the same line matching 'rq=cpu_rq*' may still exist in the function.)
+
+
 EXAMPLES
 --------
 Display which lines in schedule() can be probed:
@@ -95,6 +113,12 @@ Add a probe on schedule() function 12th line with recording cpu local variable:
 
  this will add one or more probes which has the name start with "schedule".
 
+ Add probes on lines in schedule() function which calls update_rq_clock().
+
+ ./perf probe 'schedule;update_rq_clock*'
+ or
+ ./perf probe --add='schedule;update_rq_clock*'
+
 Delete all probes on schedule().
 
  ./perf probe --del='schedule*'

tools/perf/builtin-probe.c

@@ -175,22 +175,24 @@ static const struct option options[] = {
 		opt_del_probe_event),
 	OPT_CALLBACK('a', "add", NULL,
 #ifdef NO_DWARF_SUPPORT
-		"[EVENT=]FUNC[+OFFS|%return] [ARG ...]",
+		"[EVENT=]FUNC[+OFF|%return] [ARG ...]",
 #else
-		"[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
+		"[EVENT=]FUNC[+OFF|%return|:RL|;PT][@SRC]|SRC:AL|SRC;PT"
+		" [ARG ...]",
 #endif
 		"probe point definition, where\n"
 		"\t\tGROUP:\tGroup name (optional)\n"
 		"\t\tEVENT:\tEvent name\n"
 		"\t\tFUNC:\tFunction name\n"
-		"\t\tOFFS:\tOffset from function entry (in byte)\n"
+		"\t\tOFF:\tOffset from function entry (in byte)\n"
 		"\t\t%return:\tPut the probe at function return\n"
 #ifdef NO_DWARF_SUPPORT
 		"\t\tARG:\tProbe argument (only \n"
 #else
 		"\t\tSRC:\tSource code path\n"
-		"\t\tRLN:\tRelative line number from function entry.\n"
-		"\t\tALN:\tAbsolute line number in file.\n"
+		"\t\tRL:\tRelative line number from function entry.\n"
+		"\t\tAL:\tAbsolute line number in file.\n"
+		"\t\tPT:\tLazy expression of line code.\n"
 		"\t\tARG:\tProbe argument (local variable name or\n"
 #endif
 		"\t\t\tkprobe-tracer argument format.)\n",

tools/perf/util/probe-event.c

@@ -119,14 +119,14 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 	char c, nc = 0;
 	/*
 	 * <Syntax>
-	 * perf probe [EVENT=]SRC:LN
-	 * perf probe [EVENT=]FUNC[+OFFS|%return][@SRC]
+	 * perf probe [EVENT=]SRC[:LN|;PTN]
+	 * perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
 	 *
 	 * TODO:Group name support
 	 */
 
-	ptr = strchr(arg, '=');
-	if (ptr) {	/* Event name */
+	ptr = strpbrk(arg, ";=@+%");
+	if (ptr && *ptr == '=') {	/* Event name */
 		*ptr = '\0';
 		tmp = ptr + 1;
 		ptr = strchr(arg, ':');
@@ -139,7 +139,7 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 		arg = tmp;
 	}
 
-	ptr = strpbrk(arg, ":+@%");
+	ptr = strpbrk(arg, ";:+@%");
 	if (ptr) {
 		nc = *ptr;
 		*ptr++ = '\0';
@@ -156,7 +156,11 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 	while (ptr) {
 		arg = ptr;
 		c = nc;
-		ptr = strpbrk(arg, ":+@%");
+		if (c == ';') {	/* Lazy pattern must be the last part */
+			pp->lazy_line = strdup(arg);
+			break;
+		}
+		ptr = strpbrk(arg, ";:+@%");
 		if (ptr) {
 			nc = *ptr;
 			*ptr++ = '\0';
@@ -165,23 +169,20 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 		case ':':	/* Line number */
 			pp->line = strtoul(arg, &tmp, 0);
 			if (*tmp != '\0')
-				semantic_error("There is non-digit charactor"
-						" in line number.");
+				semantic_error("There is non-digit char"
+					       " in line number.");
 			break;
 		case '+':	/* Byte offset from a symbol */
 			pp->offset = strtoul(arg, &tmp, 0);
 			if (*tmp != '\0')
-				semantic_error("There is non-digit charactor"
+				semantic_error("There is non-digit character"
 						" in offset.");
 			break;
 		case '@':	/* File name */
 			if (pp->file)
 				semantic_error("SRC@SRC is not allowed.");
 			pp->file = strdup(arg);
 			DIE_IF(pp->file == NULL);
-			if (ptr)
-				semantic_error("@SRC must be the last "
-					       "option.");
 			break;
 		case '%':	/* Probe places */
 			if (strcmp(arg, "return") == 0) {
@@ -196,23 +197,32 @@ static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
 	}
 
 	/* Exclusion check */
+	if (pp->lazy_line && pp->line)
+		semantic_error("Lazy pattern can't be used with line number.");
+
+	if (pp->lazy_line && pp->offset)
+		semantic_error("Lazy pattern can't be used with offset.");
+
 	if (pp->line && pp->offset)
 		semantic_error("Offset can't be used with line number.");
 
-	if (!pp->line && pp->file && !pp->function)
-		semantic_error("File always requires line number.");
+	if (!pp->line && !pp->lazy_line && pp->file && !pp->function)
+		semantic_error("File always requires line number or "
+			       "lazy pattern.");
 
 	if (pp->offset && !pp->function)
 		semantic_error("Offset requires an entry function.");
 
 	if (pp->retprobe && !pp->function)
 		semantic_error("Return probe requires an entry function.");
 
-	if ((pp->offset || pp->line) && pp->retprobe)
-		semantic_error("Offset/Line can't be used with return probe.");
+	if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe)
+		semantic_error("Offset/Line/Lazy pattern can't be used with "
+			       "return probe.");
 
-	pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
-		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
+	pr_debug("symbol:%s file:%s line:%d offset:%d return:%d lazy:%s\n",
+		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
+		 pp->lazy_line);
 }
 
 /* Parse perf-probe event definition */
@@ -456,6 +466,8 @@ static void clear_probe_point(struct probe_point *pp)
 		free(pp->function);
 	if (pp->file)
 		free(pp->file);
+	if (pp->lazy_line)
+		free(pp->lazy_line);
 	for (i = 0; i < pp->nr_args; i++)
 		free(pp->args[i]);
 	if (pp->args)